Repetitive Learning Control of Inverter System & Its DSP+FPGA Implementation

The purpose of a voltage controller for inverter is to produce stable and regulated output voltage with low waveform distortion under all loading conditions, especially under nonlinear loads. The repetitive learning control was proposed for inverter system to shape the waveform with low total harmonic distortion due to the dead time of the leg of inverter and nonlinear loads. In the proposed inverter system, the field programmable gate array (FPGA) is used to control generation of the basic periodic waveform, and the digital signal processors (DSP) to control compensation of output voltage waveform distortion. Based on the FPGA´s nearly parallel working feature, therefore, the output voltage of the inverter´s dependability and continuity can be ensured. The repetitive control strategy based on DSP can improve the output voltage quality of inverter. Thus, the proposed inverter controller has been verified as the better adaptability and control robustness of inverter via simulation and experimental results.